Given a sorted linked list, delete all nodes that have duplicate numbers, leaving only distinct numbers from the original list.
For example,
Given 1->2->3->3->4->4->5, return 1->2->5.
Given 1->1->1->2->3, return 2->3.
Solution:
/**
* Definition for singly-linked list.
* public class ListNode {
* int val;
* ListNode next;
* ListNode(int x) { val = x; }
* }
*/
public class Solution {
public ListNode deleteDuplicates(ListNode head) {
ListNode dummy = new ListNode(0);
dummy.next = head;
ListNode pre = dummy;
while(pre.next!=null){
ListNode cur = pre.next;
while(cur.next!=null && cur.val==cur.next.val){
cur = cur.next;
pre.next = cur.next;
}
if(pre.next==cur) pre = cur;
}
return dummy.next;
}
}